These RTS options might be used (a) to avoid a GHC bug, (b) to see
"what's really happening", or (c) because you feel like it. Not
recommended for everyday use!

`-B':

Sound the bell at the start of each (major) garbage collection.
Oddly enough, people really do use this option! Our pal in Durham
(England), PaulCallaghan, writes: "Some people here use it for a
variety of purposes -- honestly! -- e.g., confirmation that the
code/machine is doing something, infinite loop detection, gauging cost
of recently added code. Certain people can even tell what stage [the
program] is in by the beep pattern. But the major use is for annoying
others in the same office..."

`-I':

Use the "debugging mini-interpreter" with sanity-checking; you have
to have an appropriately-compiled version of the prelude, etc.
Goes together nicely with GDB (GNU debugger)...
(OLD, REALLY)

`-r<file>':

Produce "ticky-ticky" statistics at the end of the program run.
The `<file>' business works just like on the `-S' RTS option (above).
"Ticky-ticky" statistics are counts of various program actions
(updates, enters, etc.)
The program must have been compiled using
`-fstg-reduction-counts'
(a.k.a. "ticky-ticky profiling"), and, for it to be really useful,
linked with suitable system libraries. Not a trivial undertaking:
consult the installation guide on how to set things up for
easy "ticky-ticky" profiling.

`-T<num>':

An RTS debugging flag; varying quantities of output depending on which bits
are set in <num>.

`-Z':

Turn off "update-frame squeezing" at garbage-collection time.
(There's no particularly good reason to turn it off.)